Initial port of organic tree support from PrusaSlicer (#1938)

* Initial port of organic tree support from PrusaSlicer

* Port missing Organic support parameters from PrusaSlicer

* Update parameter naming

* Reorganize the `raft_first_layer_expansion` and `raft_first_layer_density` parameters as they are not only used by rafts

* Reset support style only in simple mode

* Sync latest update from PrusaSlicer & copyrights

* Fix organic tree support crash with invalid parameters

---------

Co-authored-by: Vojtech Bubnik <bubnikv@gmail.com>

src/libslic3r/Support/OrganicSupport.hpp

@@ -0,0 +1,43 @@
+///|/ Copyright (c) Prusa Research 2023 Vojtěch Bubník @bubnikv
+///|/
+///|/ PrusaSlicer is released under the terms of the AGPLv3 or higher
+///|/
+#ifndef slic3r_OrganicSupport_hpp
+#define slic3r_OrganicSupport_hpp
+
+#include "SupportCommon.hpp"
+#include "TreeSupport.hpp"
+
+namespace Slic3r
+{
+
+class PrintObject;
+
+namespace FFFTreeSupport
+{
+
+class TreeModelVolumes;
+
+// Organic specific: Smooth branches and produce one cummulative mesh to be sliced.
+void organic_draw_branches(
+    PrintObject                     &print_object,
+    TreeModelVolumes                &volumes, 
+    const TreeSupportSettings       &config,
+    std::vector<SupportElements>    &move_bounds,
+
+    // I/O:
+    SupportGeneratorLayersPtr       &bottom_contacts,
+    SupportGeneratorLayersPtr       &top_contacts,
+    InterfacePlacer                 &interface_placer,
+
+    // Output:
+    SupportGeneratorLayersPtr       &intermediate_layers,
+    SupportGeneratorLayerStorage    &layer_storage,
+
+    std::function<void()>            throw_on_cancel);
+
+} // namespace FFFTreeSupport
+
+} // namespace Slic3r
+
+#endif // slic3r_OrganicSupport_hpp